A yearly follow-up program, involving over 1600 patients with aortocoronary vein bypass operation has been organized during the initial period of this project and is in its fourth year of operation. We propose to continue the program in order to learn about the long-term association between the risk factors, especially elevated plasma lipid levels and the impairment of vein graft patency, such as already observed development of vein graft atherosclerosis. The long-term socioeconomic impact of the bypass operation expressed in terms of return to gainful employment and resumption of recreational activities will also be evaluated. The needed information will be obtained during the yearly visits of the patients, from plasma lipid analyses, results of autopsies or reoperation and post-surgery cardiac catheterization.